Control mechanism



Feb. 1'9, 1946. J. N. GooD k2,395,180

QONTROL MECHANISM Original Filed July 30, 1942 g 5? 5 ASTERN Q2 ASTERNiOO I 59 #MII ATTORNEY Patented Feb. 1.9, 1946' 2.395.180 CONTROLM'ECHANISM John N. Good, Wilmerding, Pa., assigner to The WestinghouseAir Brake Company, Wilmerding, Pa., a corporation of Pennsylvania'Original application July 30, 1942, Serial No.

452,950. 'Divided and this applicationNovember 27, 1943, SerialNo.1512,007

(Cl. 'I4-471) 3 Claims.

This invention relates to control mechanism and more particularly tomeans embodying a single control` member arranged to selectively controla plurality of devices; the present appli- 4cation being a division ofmy copending application, Serial No. 452,950, nled July 30, 1942.

The principal object of the invention is the provision of type.

Other objects and advantages will be apparent from the following moredetailed description of thel invention.

In the accompanying drawing; Fig. 1 is a diagrammatic view, partly insection and partly in outline, of a control system for a plurality ofengines embodying the invention; Fig. 2 is a vertical sectional view ofan operator's controller taken on th line 2 2 in Fig. 1; and Fig. 3 is asectional view taken on the line 3--2 in Fig. 2.

Description In the drawing, the reference numerals I and 2 indicate twointernal combustion engines which may be of the Diesel type, and both ofwhich are arranged to be connected to operate a common propeller shaft 3through the medium of suitable clutches 4 and 5, respectively, and adevice t Acontaining suitable gearing (not shown).

The clutches 4 and 5 may be of any desired type arranged for operationby fluid under pressure supplied thereto to connect the respectiveengine to the propeller shaft 3 and to disconnect said engine from thepropeller shaft upon the release of such fluid under pressure. f

Associated with engine I is a pneumatic start, ing control device Iarranged to be conditioned by fluid under pressure supplied through 'apipe 8 to provide for operation of said engine in one direction andthrough a pipe 9 to provide for operation of said engine in the reversedirection.

A fuel supply device I is associated with eneine I and embodies anadjustable member II for varying the fuel supply to and thereby thespeed or .power output of said engine. For adjusting the member Il itmay be connected to one end of a lever I2 which is iulcrumedintermediate its ends. The opposite end of lever' I 2 may be connectedto a piston I3 `contained in a cylinder I I and subject on one side tothe pressure of a calibrated spring 15. At the opposite side of pistonI3 is a pressure chamber I6 connected to a pipe I I through which iluidunder pressure may be supplied to and released from said chamber foradjusting the position of piston I3 in cylinder I4 and thereby theposition of the fuel governing member I I in'y accordance with thepressure of such fluid. With chamber IB at substantially atmosphericpressure spring I will urge the piston I3 to the position shown whichidling speed. When the piston I3 is moved in its -an improved means ofthe above cylinder by uid pressure supplied to chamber I6 to a position,for instance, substantially midway of the length of the cylinder III, itmay be assumed that the fuel supply member II will be positioned Atoprovide for maximum speed or power output of the engine I. Intermediatepositions of the piston I 2, dependent upon the pressure of fluid inchamber It, will therefore provide corresponding intermediate degrees ofspeed or power output of engine I.

Associated with engine 2 is a pneumatic starting control device I2 likethe device I but controlled by fluid under pressure from pipes I9 and22. The engine 2 has a fuelgoverning device 2i embodying a member 22adjustable by a lever 22 in accordance with the position of a. piston 22in a cylinder 25 as determined by the pressure of a spring 26 acting onone side o f the piston and the Aopposing pressure of fluid suppliedthrough a pipe 2l to a pressure chamber 22 to act on the opposite sideof saidA piston. The piston 2t may have a position such as shown toprovide for operation of the engine at idling speed and other positionsdepending upon the pressure or" fluid in chamber 2B to providecorresponding speeds or degrees of power output as described inconnection with piston I2 associated with engine I.

A manually adjustable control device 32 of any suitable type is providedfor controlling the pressure of iluid in pressure chambers I t and 22and thereby the adjustment of pistons I2 and 2t and the speed or poweroutput of engines I and 2, respectively. To accomplish this end thedevice 30 is connected to a pipe 3l which is arranged to beopened'through cutoff valvedevices 32 and 33 to pipes I I and 2l leadingto the pressure chambers I6 and 28, respectively. With the pressurechambers IB and 28 thus connected to the control device 30 said deviceis operative to either open both of said chambers to the atmosphere toprovide for operation of engines I and 2 at their idling speeds or tosupply fluid at any desired pressure from a fluid pressure supply pipe34 to both of said chambers to cause operation of said engines at achosen higher speed or degree of power output.

The cutoff valve device 32 is provided to render the engine Inon-responsive to an increase in fluid pressure provided in pipe 3| byoperation of control valve vdevice 30, if it is desired that the engineI be disconnected from the propeller shaft 3 and be operating at idlingspeed, while the engine 2 is operating said shaft to propel the craft ata speed determined -by operation of the control valve device 30. Thecuto valve device 33 is provided to accomplish the same result, withrespect to engine 2.

Both of the cutoff valve devices 33 and 32 may be of the sameconstructiomeach comprising a double beat valve 35 having one positionfor opening communication between pipe 3| and the respective pipe l1 or21 and another position for closing such communication land opening thelatter pipe I1 or 21 to atmosphere. A spring 36 in each cutoff valvedevice is operative to move the. double beat valve 35 to the positionfor connecting pipe 3| to pipe I1 or 21, while an electromagnet 31 isarranged for operation upon energization to move the, double beat valveto its other position for closing communication between pipe 3| and pipe|1 or 21 and opening the latter to atmosphere.

'I'he electromagnets 31 of the cuto valve devices 32 and 33 are arrangedto be energized by electric current from any suitable source such as abattery 38. A manually operative switch 39 is provided in the circuit tomagnet- 31 of the cutoff valve device 32, while a corresponding switch40 is provided in the circuit to the magnet of the cutoff valve device33. Closing these switches is arranged to effect energization of therespective electro-magnets while opening the switches is arranged toeffect deenergization of said magnets. With the magnets deenergized, 'itwill therefore be seen that the engines and 2 will operate in accordancewith operation of the Imanual control device 30, and that with themagnets energized the engines will be nonresponsive to operation of thecontrol device 30 and will operate only at idling speed. These switchesand the cutoff valve devices 32 and 33 are therefore effective to cutout either one engine or the other, as desired.

A manual control device 45 is provided for controlling the startingcontrol device 1 and the clutch 4 for engine l. This manual controldevice also embodies means controlled from pipe 3| for preventingoperation of clutch 4 to connect engine l to the propeller shaft 3 witheither engine operating above a chosen low speed, such as idling. Asimilar manual control Vdevice 46 is provided for controlling thestarting control device |8 and clutch 5 for engine 2 and is alsoprovided with means controlled from the speed control pipe 3| forpreventing engagement of clutch with either engine operating above achosen low speed, such as idling. Means are also provided for preventingoperation oi' both of the manually controlled devices 45 and 46 toconnect both engines and 2 to the propeller at the same time when theengines are operating in directions which would cause the propeller toturn in opposite directions. y

Each of the two similar control devices 45 and 46 is constructed inaccordance with the present invention, and the construction oi' theformer will now be described in detail.

The control device 45 comprises a casing having two spaced alignedbearings 49 and 50 in which a rock shaft 5| is journaled. A cage 52interposed between and bearing against the adjacent ends of bearings 49and 50 has aligned openings through which the shaft 5I extends, Betweenthe bearings 49 and 50 the shaft 5| has a slot 53 extendingdiametrically therethrough and the cage 52 has an aligned slot 54. Anoperating member 55 of sustantial disk form is disposed in slot 53 andextends into slot 54 and is journaled at its axis on a-pin 56. The pin56 is arranged at right angles t0 the axis of shaft 5| and is carried insuitable bores in said shaft at opposite sides of slot 53 and in theadjacent portions of cage 52. The thickness of the operating member 55is-less than the width of slots 53 and 54 only sufliciently to providefree rocking movement about the pin 56. The cage 52 being secured toshaft 5| by pin 55 holds the rock shaft 5| against endwise movement.

The operating memberv 55 is formed on one end of a lever 51 and from theabove description it will be seen that the pin 56 provides for rockingof said lever and member on said pin relative to the rock shaft 5| inthe direction of the length of said shaft, while said rock shaftprovides for movement of said lever and operating member at right anglesto the axis 0f the shaft, the operating member 55 under this lattercondition providing an operating connection between said lever and shaftfor turning the shaft with the lever.

A starting control valve device 82 is provided Y in the casing at oneside of rock shaft 5| beyond the.adjacent end of pin 56. This device comprises a vertically movable plunger 83 (Fig. 3) and valve means (notshown) operable upon downward movement of said plunger to supply fluidunder pressure from the supply pipe 34 to the starter control pipe 9 foractuating the starter control device 1 to provide for starting of theengine in one direction. It may be assumedthat with the engine operatingin this direction the propeller shaft 3 when connected to said enginewill cause movement of the ship in a forward direction. Movement of theplunger 83 in an upward direction as viewed in Fig. 3 is arranged toallow release of fluid under pressure from the starter control pipe 9 toprovide for stopping of the engine or for starting of the engine in theopposite direction, as will be later described. For controlling theplunger 83 one end of a lever 84 bears against the plunger. This leveris supported on a pin 85 secured in the casing while the opposite end isprovided with a roller 88 arranged to contact a cam surface 81 providedon the cage 52 above one end of pin 56 and adjacent the top of operatingmember 55. Movement of the member 51 toward the left-hand as seen inFig. 3 or upward as viewed in Fig. 1,' to a position bearing the legendForward is arranged to operate cam 81 and thereby the lever 84 to movethe plunger 83 in a downward direction for supplying fluid underpressure to the starter control pipe 9, while movement of said leverback to its normal position shown is arranged to provide for movement ofthe plunge'. 83 in the reverse direction for releasing fluid underpressure from pipe 9.

At the opposite side of shaft 5| and beyond the opposite end of pin 56is a starting control valve device 88 which may be identical to thedevice 82 and which comprises a plunger 89 operable upon downwardmovement to supply fluid under pressure from the supply pipe 34 to pipe8 leading to the starter control device 1 to provide for operation ofsaid device to cause starting of the engine in the direction of thereverse of that attained by the supply of fluid under pressure to pipe9. or in a direction to cause movement of the ship in an asterndirection when connected to the propeller shaft 3, as indicated by thelegend "Astern" in Figs. 1 and 3.

A lever 90 like lever 84 is arranged for controlling movement of plunger89, and the cage 52 is provided with a cam 8| opposite the cam 81 foroperating the lever 88. By this construction movement of the operatinglever 51 downwardly as viewed in Fig. 1 or in the direction of theright-hand, as viewed in Fig. 3, will actuate the valve device 88 tocause starting of the engine in the direction to provide for asternmovement of the ship, while return of the lever 51 to the neutralposition shown will provide for operation of the valve device 88 torelease fluid under pressure from pipe 8 in order to effect stopping orreversal of the engine.

A more detailed description of the structure and operation of the valvedevices 82 and 88 is not deemed essential since devices of this type arewell known to those skilled in the art.

The top wall4 9| of the casing of the control valve device 45 isprovided with a relatively long slot 92 extending at right angles to theaxis of rock shaft 5|. This slot provides for movement of the lever 51to either Forward position or "Astern position for actuating the startercontrol valve devices 82 and 88 respectively for starting the engine Iin either one direction or in the reverse direction as above described,and to the neutral position for stopping the engine. It will be seenthat this slot prevents movement of the lever 51 in' any directionexcept for'operating the valve devices 82 or 88.

A clutch control device 60 is associated with the easing bearing 50beyond the journaled end of shaft 5|. This -device comprises twooppositely seating poppet valves 6I and 62 arranged in coaxial relationwith rock shaft 5| and contained in chambers 63 and -6-1, respectively.These valves have fluted stems extending toward each other throughsuitable bores in the device and meeting in'a chamber 65. The chamber 63is connected by a pipe 66 to the fluid pressure supply pipe 34 andcontains a spring l61 acting on the valve 6| for seating `same and atthe same time unseating the valve 62. The chamber 65 is connected by apipe 68 to the clutch 4 for engine I. The chamber 64 is open through apassage 69 to the interior of the casing and thus with the atmospherethrough openings including slot 92.

-The rock shaft 5| between the operating member and valve (i2v isprovided with an axial bore in which is slidably mounted a plunger 18.One end of this plunger engages the valve 62 while the other end isaligned for engagement by the peripheral surface of the operating member55 at one side of pin 56. The operating member 55 has in its peripheralsurface a recess 1| arrange-d to receive the adjacent end of plunger 18when the operating lever 51 is in the vertical position shown in Figs. 1and 2. With the plunger 18 in recess 1| spring 61 is operative to seatvalve 6| and open valve 62 to thereby connect the clutch control pipe 68to the atmosphere for effecting operation of the clutch 4 to disconnectthe engine I from the propeller shaft. Movement of the leverl 61 fromthis vertical position in either a clockwise direction orcounterclockwise direction, as viewed in Fig. 2, is adapted to turn theoperating member 55 to a position in which a portion at either one sideor the other of recess 1I is in engagement with the plunger 10 andduring such movement to effect movement of the plunger 18 outwardly ofshaft 5| to seat valve 62 and unseat valve 8|. With the valve 8| thusopen fluid under` pressure will flow from the supply pipe 34 to pipe 68and thence to clutch 4 for effecting operation thereof to connect theengine I to the propeller y shaft 3.

In order that the lever 61 may be operated as just described iorcontrolling the operation of the clutch 4, the top wall 9| of the casingis provided with two oppositely extending slots 93 and 94 opening to theopposite sides of the slot 92 adjacent its opposite ends. It will beseen that since engagement of the clutch 4 is dependent upon movement'of the lever 51 in either a clockwise or counterclockwise directionfrom the position shown in Fig. 2 and thus out of the slot 92, theclutch will be disengaged with the lever in the slot 92 and be engagedonly upon movement into the slot 93 or into the slot 94.

In use, let it be assumed that; the lever 61 is in its neutral positionmidway between the ends of slot 92 as shown in Figs. 1 and 3. If it isnow desired to start the engine I in such a direction ras to causeoperation of the propeller shaft 3 to move the ship forwardly the lever51 is moved in slot 92 to "Forward position for thereby operating thestarter control valve device 82 to cause the engine I to be started in adirection to obtain forward movement of the ship. After the engine isthus started, the lever 51 is drawn back from the end oi slot 92 to aposition aligned with slot 93 and then moved into the latter slot foroperatu ing the clutch control device 68 to supply fluid under pressureto pipe 68 foractuating the clutch 4to connect the engine i to thepropeller shaft 3. whereupon the engine will operate the propeller ofthe ship to cause movement 0f same in a forward direction.

On the other hand, if it is desired that the ship move in an asterndirection, the lever 51 is moved either from its neutral position, orfrom Forward position through its neutral position which causes stoppingof the engine, to its Astern position at the opposite end of slot 92 tothereby actuate the starter control valve device 88 to supply fluidunder pressure to pipe 8 for causing the engine I to be started in thereverse direction. 'I'he lever 51 may be then moved away from the end ofslot 92 into alignment with slot 94 and then into the latter slot foractuating the clutch control device 6|) to supply fluid under pressureto pipe 68 for operating the clutch 4 to connect the engine to thepropeller shaft 3 for causing movement of the ship in an asterndirection.

It will be seen that with lever 51 in slot 92 the clutch control pipe 68Will be opened to atmosphere by way of the clutch control device 68 toeffect operation of `the clutch 4 to disconnect the engine I from thepropeller shaft 3. Connecting the engine to the propeller shaft isobtained only upon movement of the lever into either slot 93 or slot 94.The slot 92 provides for starting of l the lever in substantialalignment with the upper end of cage 52. A friction shoe |00 is slidablymounted on lever 51 between the spring seat 96 and inner surface 98 ofthe top wall of the casing. A coil spring 99 under pressure encirclesthe lever 51 and is supported at one end on the spring seat 96 and bearsat the opposite end against the friction shoe for constantly urging saidshoe against the inner surface 98 of the casing.

Theinner surface 98 is substantially in the shape of an inverted V inthe direction of the length of slot 92 and in said surface adjacent eachof the opposite ends of said slot is a recess IDI arranged to receivethe shoe |00 upon movement of the lever into alignment with either ofthe slots 93 or 94. With the shoe |00 engaging the surface 98 at anypoint between the two recesses IOI the force of the spring 99 againstsaid shoe is operative to automatically return the lever 51 to itsneutral position shown in Fig. 3. When the shoe |00 is in either of therecesses |0I, the lever 51 is held against movement toward neutralposition. By this arrangement it is necessary for the operator to movethe lever 51 substantially to either one end or the other of slot 92 inorder that the lever will not return to its neutral position shown uponremoval of manual force on the lever. This insures adequate movement ofthe lever to cause starting of the engine in either one direction or theopposite, as desired, and also provides for the lever being held in itsclutch engaging positions in slots 93 or 94 due to interlocking of thefriction shoe |00 Within the recesses IOI, and also due to the fact thatthe surface 98 lengthwise of these recesses is arranged at substantialright angles to the normal or neutral position of lever 51 in slot 92.

A clutch and speed interlock device is secured to the casing over theopposite end of rock shaft 5|. This device comprises a piston 16 havingat one side a chamber 11 open to the speed or power output control pipe3|. Projecting from the opposite face of piston 16 is a plunger 1-8which slidably extends through a suitable axial bore in the adjacent endof shaft 5| into alignment with the peripheral surface of the operatingmember 55 directly opposite that engaged by the plunger 10. Theoperating member 55 has a notch or recess 19 provided in its peripheryin such a position as to receive the end of plunger 18 when the lever 51is in slot 92 in which the clutch 4 disconnects the engine I from thepropeller shaft. A coil spring 80 encircling the plunger 18 bears at oneend against the adjacent end of rock shaft 5| and the opposite end bearsagainst piston 16 in opposition to pressure of `uid effective in chamber11.

As above described, the speed or output of engine I is varied accordingto the pressure of iiuidsupplied to act in pipe 3| and opening of saidpipe to atmosphere provides for idling operation of said engine. Thepressure of spring 80 on piston 16 in the interlock device 15 is such asto move said piston and Vplunger 18 to the position shown when thepressure in pipe 3| and thereby chamber 11 is at a chosen low degree, orsubstantially that of the atmosphere if desired, and to permit thepiston to move the plunger 18 against the operating member 55 when thepressure in said pipe is increased above that degree. Thus if enginev lshould be operating at a speed above the chosen low degree with thelever 51 in slot 92, the plunger 18 will enter recess 19 and preventturning of member 55 and thus maintain the clutch 4 in the positiondisengaglng engine I from the propeller shaft 3. To rock the lever 51 ineither direction from the clutch disengaging position shown in Fig. 2 tocause operation of clutch 4 to connect engine I to the propeller shaft3, the pressure in the speed control pipe 3| and piston chamber 11 onthe interlock piston 18 must therefore be reduced to a degree whichprovides for operation of the engine at the chosen reduced speed. Whenthis occurs, spring 80 will move the piston 16 and plunger 18 to theposition shown in Fig. 2 in which the plunger 18 is removed from notch184 When this condition exists, the lever 51 may be moved into either ofthe slots 93 or 94 for actuating the clutch 4 to connect the engine to.the propeller shaft 3. In other Words, the interlock valve device 15controlled from the speed control pipe 3| prevents the operator movinglever 51 into either of the slots 93 or 94 for actuating the clutch 4 toconnect the engine I to the propeller shaft 3 when the engine isoperating at a speed above a chosen low degree.

The manual control device 46 may be identical to the manual controldevice 45 and like reference numerals have therefore been applied to themain corresponding portions of the control device 46. In Fig. 2 it willbe seen that the clutch control device 60, interlock valve device 15,and operating member 55 are disposed in -the control -device 46 just thereverse of corresponding parts in the control device 45 but this in noWay changes the operation of the engine 2 as controlled by the startingcontrol device I8 or of clutch 5 in response to operation of lever V51in the control device 46 in slots 92, 93 and 94 which are identical tocorresponding slots providing for controlling movement of lever 51 inthe control device 45. The operator may, therefore, move lever 51 of thecontrol device 48 upward in slot 92, as viewed in Fig. 1, to "Forward"position for causing starting of the engine 2 in a direction to propelthe ship forwardly and then into the slot 92 for actuating clutch 5 toconnect the engine to the propeller shaft 3, or he may move said leverto the opposite end of slot 92 to "Astern" position for causing startingof the engine 2 in a direction for moving the ship in an asterndirection and then move said lever into.

slot 94 for actuating the clutch 5 to connect said engine to thepropeller shaft 3, these operations being the same as in the controldevice 45 and producing the same results with respect to engine 2.Moreover, movement of lever 51 of the control device 46 to actuateclutch 5 to connect engine 2 to the propeller is subject to control bythe respective interlock device 15 the saine as above described inconnection with the control device 45.

If the operator desires to connect both engines I and 2 to the propellershaft 3 at the same time for driving theship, he may move both levers 51in the same direction to either one end or the opposite end of slots 92land then into either slots 93 or 94, respectively, as will be apparent.

However, if one engine is already connected to the propeller shaft atthe time it is desired to connect the other engine to said shaft, theinterlock device 15 of the controller 45 or 48 control--r ling thelatter engine requires that the pressure in the speed control pipe 3| besuch as to provide for idling operation not only of the respectiveengine, as above described, but also of the other engine and thereby ofthe propeller shaft 3, since said interlock device is controlled by thesame pressure as controls the speed of the other engine. The interlockvalve device thus precludes the possibility of connecting either engineto the propeller shaft when said shaft is being 2,895,180 ldriven by theother engine operating at a speed above idling.

Summary It will now be seen that each of the manually operative controldevices 45 and 48 provides for selective control o a plurality ofdiiferent devices by means of a single controlling lever. The lever iscarried by and so connected to a rock shaft as to be capable of rockingsaid shaft for controlling one of the devices. The connection betweenthe4 rock shaft and lever also provides for rocking movement of saidlever in a direction lengthwise of the rock shaft, without rocking therock shaft. for actuating a plunger carried axially of the rock shaftfor controlling another of the devices. Means carried by the rock 'shaftaxially thereof are also provided for interlocking with the lever toprevent rocking move.-

ment of the lever lengthwise of the rock shaft in order to prevent acertain undesired operation. In order to ensure a desired squence ofoperations, means are provided to prevent operation of the lever to rockthe rock shaft while operating the plunger therein and topreventoperation of said plunger while rocking the rock shaft.

Having now described myinvention. what l claim as new and desire tosecure by Letters Patent is:

l. A device for controlling the operation of two separate devicescomprising a casing, a rock shaft journaled in said casing forcontrolling one of said devices and having a slot extendingdiametrically therethrough. a member disposed in said slot, and having aJournal connection with said rock shaft diametrically thereof, saidmember being rockable relative to said rock shaft for operating theother of said devices and being operable upon movement in a directionabout the axis of said rock shaft forrocking said rock shaft. a leverassociated with said member for operating same, a plunger at one side ofsaid slot slidably mounted in an axial bore in said rock shaft, saidmember having a recess for receiving said plunger in one position ofsaid member for holding said member against movement relative to saidrock shaft but providing for rocking movement of said rock shaft, andmeans for controlling movement or said plunger into and out of saidrecess.

2. A device for controlling the operation of two separate devicescomprising a casing, a rock shaft Journaled in said casing forcontrolling one of said devices and having a slot extendingdiametrically therethrough, a member disposed in said slot and having ajournal connection with said rock shaft diametrically thereof, saidmember being rockable relative to said rock shaft and being operableupon movement in a direction about the axis of said rock shaft forrocking said rock shaft, a lever associated with said member foroperating same, a plunger at one side of said slot slidably mounted inan axial bore in said rock shaft, said member having a recess forreceiving said plunger in one position of said member for holding saidmember against movement relative to said rock shaft but providing forrocking movement of said rock shaft. means for controlling movement ofsaid plunger intoand out of said recess, and another plunger at theopposite side of said slot slidably mounted in an axial bore in saidrock shaft and engaging said member, the portion of said member engagedby the last named plunger constituting a cam operative upon movement ofsaid member about its axis to eiect movement of the last named plungeraxially of said rock shaft, the last named plunger` controlling theother of said devices.

3. A device for controlling the operation of two separate devicescomprising a casing having two spaced bearings, a rock shaft Journaledin said bearings for controlling one of said devices and having betweensaid bearings a slot extending diametrically therethrough, an elementmounted on said shaft between and engaging the adjacent ends of saidbearings, a pin arranged at right angles to said slot extendingdiametrically through said shaft at opposite sides of said slot andthrough said element securing said rock shaft against axial movement. amember disposed in said slot and journaled on said pin for rockingmovement to control the other oi. said devices. said member beingoperable upon movement in a direction about the axis of said rock shaftto rock said rock shaft, and means associated with said member foroperating same relative to said rock shaft.

JOHN N. GOOD.

